Thumb Stop Cam Height Adjusting System and Method

ABSTRACT

An adjusting system is provided. The adjusting system includes: a slug defining an eccentric hole; and a locking structure defined by an outer circumference of the slug, the locking structure dimensioned and configured to lock the slug in a rotational orientation when the slug is placed in a hole having a corresponding locking feature, the locking structure configured to permit the slug to be placed in the corresponding hole in at least two different angular orientations and lock with the locking feature in the corresponding hole at each of the at least two different angular orientations. A method for adjusting stop shoes is also provided. The method includes: rotating a slug to a desired angular orientation; inserting the slug into a hole; locking the slug to a particular angular orientation with locking structure attached to both of the slug and the hole; and securing a stop shoe to the slug.

TECHNICAL FIELD

The present disclosure relates generally to a stop system and amechanism for adjusting the stop system. More particularly, the presentdisclosure relates to a stop system for stopping a thumb against a stickon a mechanical arm and an adjusting system for adjusting features ofthe stop system.

BACKGROUND

Excavating machines often use an arm which may include a boom having astick pivotally connected to the boom. A bucket is pivotally connectedto the stick. In some instances, a thumb may also be connected to thestick which can open or close over the bucket. When the thumb is in itsextreme open position, it may contact or reside against the stick.Sometimes the thumb may contact the stick with more force than isdesired. For example, more force than desired can be caused by forceresulting from the weight of the thumb cylinder, the stick, the boom,boom cylinder, and/or the stick cylinder. In order to reduce thelikelihood of damage between the thumb and/or stick, a stop system maybe instituted to stop or butt the thumb against the stick.

Some stop systems may use a linkage. Such a system is described in U.S.Pat. No. 7,818,901. Other systems may provide structure for the thumb tobutt against on the stick. Examples of these type of systems are alsodescribed in this patent in its discussion of the prior art. The use ofa linkage as a stop system may require various links to transmit largeforces and require complicated linkages. Other stop systems may resultin large projections extending from the surface of the stick, which mayinterfere with operation of the excavating equipment.

It may be desirable to provide an adjusting system in order to adjustthe stop system to be in a desired location. Due to manufacturingtolerances, flexing of parts due to wear and/or damage, and a variety ofother reasons, the stop system may move out of a desired location aftermanufacturing of the machine. Thus, it may be desirable for theadjusting system by be adjusted after the machine has left the factory.

Some adjusting systems use a cam washer for providing an adjustment. Anexample of such a system is described in U.S. Pat. No. 5,163,699. Thecam member includes a mechanism for detachably attaching the cam memberto the nut or to the head of the bolt such that the cam member isrotatable by engagement of the nut and/or the bolt. When the cam memberis rotated, the cam member works against a cam member bearing surfacesuch that the bolt is moved sideways thereby providing adjustment.

SUMMARY

The present disclosure describes a stop system, an adjusting system forthe stop system, a method for stopping, and a method for adjusting astop system.

In the disclosure, a stop system is described. The stop system mayinclude: a first member; a second member movable with respect to thefirst member, the first and second members being different parts of acommon machine; a body including a boss defining a hole; a base plate atleast one of: attached to and part of, the body on the side of the bodyopposite of the boss, the body and base plate forming a shoe; and afastener extending through the hole in the boss thereby pivotallyattaching the body to one of the first and second members.

In the disclosure, a method of providing a stop for stopping a thumbagainst a stick is described. The method may include installing apivotable shoe on one of the thumb and stick.

In the disclosure, a stop system is described. The system includes: afirst member; a second member movable with respect to the first member,the first and second members being different parts of a common machine;a pivoting means for abutting attached to one of the first and secondmembers; and a contact surface located on the other of the first andsecond members than the pivoting means for abutting, the contact surfacelocated such that when the first and second members are in contact witheach other the pivoting means for abutting is contacting the contactsurface.

In the disclosure, an adjusting system is described. The adjustingsystem includes: a slug defining an eccentric hole; and a lockingstructure defined by an outer circumference of the slug, the lockingstructure dimensioned and configured to lock the slug in a rotationalorientation when the slug is placed in a hole having a correspondinglocking feature, the locking structure configured to permit the slug tobe placed in the corresponding hole in at least two different angularorientations and lock with the locking feature in the corresponding holeat each of the at least two different angular orientations.

In the disclosure, a method for adjusting stop shoes is also described.The method includes: rotating a slug to a desired angular orientation;inserting the slug into a hole; locking the slug to a particular angularorientation with locking structure attached to both of the slug and thehole; and securing a stop shoe to the slug.

In the disclosure, an adjusting system is described. The system mayinclude: a means for defining an eccentric hole; a means for preventingthe rotation of the means for defining an eccentric hole when the meansfor defining an eccentric hole is inserted into the means for preventingthe rotation of the means for defining an eccentric hole; means forabutting pivotally attached to the means for defining an eccentric hole;and a fastener pivotally connecting the means for abutting to the meansfor defining an eccentric hole, the fastener extending through both themeans for abutting and the eccentric hole.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side view of an excavating machine having an armincorporating an apparatus described herein.

FIG. 2 is a partial enlarged side view of the arm at the place indicatedin FIG. 1.

FIG. 3 is a partial isometric view of a stop system described herein.

FIG. 4 is a partial isometric view of a stop system described herein.

FIG. 5 is a isometric view of a stop shoe.

FIG. 6 is an end view of a stop shoe.

FIG. 7 is a top view of a stop shoe.

FIG. 8 is a side view of a stop shoe.

FIG. 9 is a bottom view of a stop shoe.

FIG. 10 is a partial cross-sectional view of a stop shoe.

FIG. 11 is a side view of a stop system.

FIG. 12 is an end view of a stop system.

FIG. 13 is a side view of the slug used as part of an adjusting system.

FIG. 14 is a partial end view of a stop and adjusting system.

FIG. 15 is a partial side view of a stop and adjusting system.

FIG. 16 is a partial isometric view of a stop and adjusting system.

FIG. 17 is a partial side view of an adjusting system showing a slug fitinto a corresponding hole.

FIG. 18 is a partial side view of another adjusting system showing aslug fit into a corresponding hole.

FIGS. 19-23 are partial side views of a stop and adjusting system wherethe adjusting system has been adjusted to place the stop shoe at variousheights.

FIG. 24 is a partial side view of another adjusting system.

FIG. 25 is a partial end view of a stop and adjusting system.

FIG. 26 is a side view of a stop and adjusting system.

FIG. 27 is a isometric view of a stop and adjusting system.

FIGS. 28-32 are partial side views of a stop and adjusting system wherethe adjusting system has been adjusted to place the stop shoe at variousheights.

FIG. 33 is a partial side view of another adjusting system.

FIG. 34 is a side view of a stop and adjusting system.

DETAILED DESCRIPTION

The apparatus and methods disclosed herein will now be described withreference to the drawing figures, in which like reference numerals referto like parts throughout. The present disclosure describes severalsystems and methods for providing a thumb stop to stop a thumb thatmoves to cover a bucket against a stick that supports the thumb andbucket. The present disclosure further describes various systems andmethods for adjusting the height of various thumb stop systems.

FIG. 1 illustrates a side view of an excavating machine 48 thatexcavates earth or other material 49. The excavating machine 48 includesan arm 50 that may be used in various pieces of excavating equipment andnot just the example machine 48 shown. The arm 50 includes a boom 52pivotally attached to a stick 54 via a pivot joint 56. The stick 54 maybe terminated with a bucket 60. The bucket 60 is pivotally connected bypivot joint 62 to the stick 54. The bucket 60 may also include a linkage64 which may be attached to a hydraulic cylinder which, is onlypartially shown to avoid overcrowding FIG. 1. The arm 50 may also beequipped with a thumb 66. The thumb 66 may be actuated by a hydrauliccylinder 58 attached to a linkage 70. The linkage 70 and other linkagethat is associated with the hydraulic cylinder 58 is not completelyshown to avoid overcrowding FIG. 1.

The thumb 66 may pivot about the pivot joint 62. The thumb 66 may move,close to or contact the bucket 60 to allow the arm 50 pickup variousobjects. Furthermore, the thumb 66 may be used as a cover for the bucket60 to avoid or hinder material contained in the bucket 60 from fallingout. When the thumb 66 is in a position distal from the bucket 60similar to that shown in FIG. 1, the thumb 66 may be proximate to oreven contact the stick 54. In order to reduce force concentration whenthe thumb 66 contacts the stick 54 in a hard manner as to potentiallydamage either the stick 54 or the thumb 66 a thumb stop system 73 may beimplemented.

FIG. 2 is a partial, expanded side view of a thumb stop system 73 at theplace indicated in FIG. 1. The thumb stop system 73 shown in FIG. 2includes a stop shoe 74 attached to a rib 72 on the thumb 66. The stopshoe 74 includes a tread plate 78 (sometimes referred to as a baseplate) and is attached to the ribs 72 by fastener 76. The tread plate 78is shown butted up against the pressure plate 84 on the underside 86 ofthe stick 54. The pressure plate 84 constitutes a contact surface forthe stop shoes 74 to butt against. In embodiments where there is nopressure plate 84 the outer surface of the stick 54 is a contactsurface. The dashed lines illustrate parts that are hidden from view dueto the presence of the thumb 66.

FIG. 3 is a partial isometric view where the thumb 66 is pivoted aboutthe pivot joint 62 away from the stick 54. The ribs 72 may be normallypresent on the thumb 66. The ribs 72 may be used to stiffen the thumb66. However, in accordance with an apparatus disclosed herein, the rib72 provides an additional function of providing a mounting place for thestop shoe 74. The stop shoe 74 is attached to the ribs 72 via a fastener76. The tread plate 78 of the stop shoes 74 are also shown.

FIG. 4 is an enlarged isometric view showing the tread plate 78 of thestop shoe 74 pressed against the pressure plate 84. According to a stopsystem 73 described herein, the stop system 73 may include a stop shoe74, a fastener 76 which include bolts 80 having bolt heads 88 and locknuts 82. The stop shoe 74 includes a body portion 90. The body portion90 has a boss 92 which may define a hole 94. It is through the hole 94that the bolt 80 extends through along with a hole in the rib 72 inorder to attached the stop shoe 74 to the rib 72.

FIGS. 5-9 respectively are isometric, end, top, side, and bottom viewsof a stop shoe 74 according to one embodiment. With reference to FIGS.5-9, the stop shoe 74 includes bodies 90, 98 and a boss portion 92.Holes 94 extend through the boss portion 92 and it is through the holes94 that the bolts 80 extend through including a hole in the rib 72 toattach stop shoe 74 to the rib 72. The hole 94 may have an opening 95.Other stop shoes 74 may not have an opening 95 but may be closed asshown in FIG. 11.

As seen in FIG. 6, the stop shoe 74 may include a second body 98 whichmay be constructed substantially the same as the first body 90. The twobodies 90, 98 may be connected via the tread plate 78. The tread plate78 may include tread plate holes 96. The tread plate holes 96 may haveopenings 102. The bodies 90 and 98 may include protrusions 100 thatextend at least partially into the holes 96 in the tread plate 78.

FIG. 10 is a partial cross-sectional view of the body 90 the tread plate78 at a hole 96 in the tread plate 78. Some stop shoes 74 may befabricated by welding the body 92 the tread plate 78 at the protrusions100 in the holes 96. FIG. 10 shows weld material 104 in the hole 96above the protrusion 100 of the body 90. Other stop shoes 74 may befabricated in other manners where the bodies 90, 98, and the tread plate78 are attached in other fashions.

FIG. 11 is a partial side view of the stop system 73 according to thedisclosure. The stop system 73 illustrates a stop shoe 74 having a body90 where the hole 94 has no opening 95. The outline of the hole 94 shownin broken line. The rib 72 also has part of the outer contour which isobscured by the presence of the stop shoe 74 shown in broken line. Thebolts 80 extend through the hole 107 to attach the stop shoe 74 to therib 72. The bolts 80 are not tightened so much as to prevent the stopshoe 74 from being able to pivot with respect to the rib 72. The rib 72may also have an opening 105 at the location of the hole 107 in the rib72.

The tread plate 78 is shown butted up against the pressure plate 84. Ifthe pressure plate 84 is not level with respect to the stop shoe 74, theinitial contact between the stop shoe 74 and the pressure plate 84 cancause the stop shoe 74 to pivot about the bolt 80 in order to have thetread plate 78 lay flat against the pressure plate 84 as the pressureplate 84 and stop shoe 74 move closer together.

FIG. 12 is a partial end view of the stop system 73. Two ribs 72 extendup from the thumb 66 and have a bolt 80 attaching the stop shoe 74 tothe rib 72. The bolt head 88 is pressed against the body 90 or 98 whilethe lock nut 82 is attached to the bolt 80 and is also pressed againstthe body either 90 or 98. The tread plate 78 is pressed against thepressure plate 84 on the stick 54 as can be seen in FIG. 12. It may bedesirable to have the height of the two tread plates 78 to be the sameso that the pressure plate 84 is contacted at the same time by the twotread plates 78. Otherwise, if the height of the tread plates 78 weredifferent, one of the stop shoes 74 will be contacted before the otherstop shoe 74 which could place uneven forces on the pressure plate 84,stick 54, and thumb 66.

In some embodiments there is no pressure plate. In such embodiments, thestop shoe 74 may directly contact the stick 54 however the same basicprinciples described herein will apply.

When the thumb 66 opens to its extreme position causing the stop shoe 74to impact the stick 54 via the pressure plate 84, the stop shoes 74 maynot only rotate about the bolt 80 they may also slide a little bit alongthe pressure plate 84. The sliding motion may be caused by thedifference in diameters of the bolt 80 and the holes 94 in the stop shoe74 and the holes 107 in the rib 72. Furthermore, the openings 95 in theholes 94 in the stop shoe 74 and opening or hole 107 in the hole 107 inthe rib 72 may facilitate minor deflections in the material forming therib 72 and or stop shoe 74 when the stop shoe 74 or rib 72 are understress. These deflections may also cause the sliding action of the treadplate 78 or surface along the pressure plate 84 and or stick 54. In someembodiments the sliding motion may be desired in that it along with apivoting of the stop shoe 74 helps with aligning the tread plate 78 withthe pressure plate 84 or stick 54 in a manner that reduces thelikelihood of gouging the pressure plate 84 or stick 54 (in instanceswhere a pressure plate 84 is absent). The sliding motion of the stopshoes 74 may also be caused, in part, by deflection of the thumb 66 andtolerances in the joint 62.

In some embodiments the size and strength of the bolts 80 may beselected so that if the thumb 66 is opened quickly, or otherwiseprovides a hard strike to the pressure plate 84 and or stick 54, thebolts 80 will shear before the stop shoes 74 dent, gouge, or damage thepressure plate 84 or stick 54. This shearing feature allows the bolts 80to act as a mechanical fuse.

An adjusting system 115 for the stop system 73 will now be described.FIG. 13 is a side view of a slug 106 having an eccentric hole 108. Theslug 106 has flats 110 which help define an outer circumference 111 ofthe slug 106. The intersection of two flats 110 form a corner 112 on theouter circumference 111 of the slug 106. The flats 110 and corners 112comprise part of the locking structure 113 on the outer circumference111 of the slug 106. The slug 106, together with the locking structure113, provides part of an adjusting system 115 for a stop system 73 (seeFIG. 11).

The slug 106 has a center 114. The eccentric hole 108 has a center 116that is significantly offset 118 from the center 114 of the slug 106. Byrotating the slug 106 about its center 114, the height of the eccentrichole 108 will vary. As result, in instances where a slug 106 having aneccentric hole 108 is used as part of the adjusting system 115,adjustments in height can be made by rotating the slug 106.

FIG. 14 is an end view of a stop system 73 having a stop shoe 74 and anadjusting system 115 for adjusting the height of the stop shoe 74 withrespect to the rib 72. The stop system 73 shown in FIGS. 14-16 has adifferent stop shoe 74 than shown in the previous figures. For example,the stop shoe 74 includes a body 120 that is made of a single piece offolded metal. The body 120 has a tread surface 122 rather than aseparate tread plate 78 as described above. The portion of the body 120defining the tread surface 122 may be referred to as a base plate.Optionally, a separate tread plate 78 could be attached to the body 120.In some instances the body 120 may be made of steel. The body 120 stillhas a boss 92 and a hole 94 similar to those features described above.

A fastener 76 (which may include a bolt 80 and lock nut 82) attaches thestop shoe 74 to the rib 72 in a manner similar to that described above.A bolt 80 extends through the hole 94 securing the body 120 between alock nut 82 and the bolt head 88.

FIGS. 15 and 16 are side and isometric views respectively of a stopsystem 73 including an adjusting system 115. The stop system 73 and theadjusting system 115 include a slug 106 fit into a hole 124 in the rib72. The hole 124 has a corresponding shape to the slug 106 so that whenthe slug 106 is fit into the hole 124, the slug 106 is unable to rotatewithin the hole 124. A fastener 76 connects the stop shoe 74 to the slug106 and in turn connects the stop shoe 74 to the rib 72. The fastener 76extends through the eccentric hole 108 as illustrated in FIGS. 15 and16,

There is an offset 126 between the tread surface 122 and the rib 72.This offset 126 can be adjusted by removing the fastener 76 the stopshoe 74 and the slug 106. Once outside the hole 124, the slug 106 can berotated to place the eccentric hole 108 into a desired position withrespect to the rib 72. Then the slug 106 is placed into the hole 124where it is rotationally locked in place. The stop shoe 74 is thenattached to the slug 106 via the fastener 76. The offset 126 can also beaffected by pivoting the stop shoe 74 about the fastener 76.

FIGS. 17 and 18 are partial side views of locking structure 113 thatincludes the slug 106 fit into a corresponding hole 124 in a rib 72. Theslug 106 shown in FIGS. 17-18 has an eccentric hole 108. The eccentrichole 108 is in its highest position. As one of ordinary skill the artcan appreciate, if the slug 106 was removed from the hole 124 androtated to a different angular orientation, the eccentric hole 108 wouldbe lowered. When the slug 106 is fit into the corresponding hole 124 theflats 110 of the outer circumference 111 of the slug 106 intersect toform corners 112. The corners 112 of the slug 106 are aligned withcorners 128 in the corresponding hole 124 of the rib 72. In this manner,the slug 106 is locked from rotating within the hole 124 about thecenter axis by the locking structure 113 which includes the flats 110,corners 112, and corners 128 in the corresponding hole 124. In FIG. 17there are the same amount of corners 128 in the corresponding hole 124as corners 112 in the slug 106.

FIG. 18 illustrates a different version of a locking structure 113 thanthat shown in FIG. 17. FIG. 18 includes a slug 106 having an eccentrichole 108 where the intersection of two flats 110 form corners 112.However the corresponding hole 124 in the rib 72 has more corners 128than corners 112 found on the outer circumference 111 of the slug 106.One reason for having additional corners 128 is it allows the lockingstructure 113 to secure the plug 106 in more positions than the lockingstructure 113 shown in FIG. 17. As such, the slug 106 can be rotated inmore positions thereby allowing finer adjustments in height to be madethan the locking structure 113 in FIG. 17.

One of ordinary skill the art will understand after reviewing thisdisclosure that the more corners 128 in the corresponding hole 124 themore height adjustments can be made to the eccentric hole 108 withoutactually increasing the extreme range between the highest and lowestpositions of the eccentric hole 108. The locking structure 113 shown inFIG. 18 illustrates twice as many corners 128 in the hole 124 in the rib72 than corners 112 on the outer circumference 111 of the slug 106.However in other embodiments, a fewer or greater number of corners 128may be used in that shown in FIG. 18.

FIGS. 19 through 23 illustrate stop systems 73 and locking structure 113where the locking structure 113 has been adjusted to allow the treadsurface 122 to be at different offsets 126 with respect to the rib 72.The fastener 76 extends into the eccentric hole 108 attaching the body90 at various heights with respect to the rib 72. The slug 106 is placedin a corresponding hole 124 to lock the slug 106 in an angular positionto thereby secure the body 90 and tread surface 122 at a particularoffset 126 with respect to the rib 72.

Where locking structures 113 are used similar to that shown in FIG. 17the body 90 and tread surface 122 can have 5 different and uniquepositions or offsets 126 with respect to the rib 72. By removing thefastener 76 and the body 90, the slug 106 can be moved axially out ofthe corresponding hole 124 and rotated to allow the eccentric hole 108to be moved to 5 different and unique positions. The body 90 can then bereplaced and the fastener 76 reinstalled at each or any of thesepositions thereby allowing the tread surface 122 to be located atvarious heights or offsets 126 with respect to the rib 72. Fivedifferent unique positions are illustrated in FIGS. 19-23.

FIGS. 24-32 illustrate a stop system 73 having a different type ofadjusting system 115. The adjusting system 115 shown in FIG. 24 includesa slug 106 located in a hole 124 in the rib 72. The slug 106 includes aneccentric hole 108 similar to the eccentric hole in the slug 106 in theadjustment system 115 described in the already mentioned and discussedfigures. The slug 106 has an outer circumference 111 that is differentthan the outer circumference 111 discussed in the previous figures. Theouter circumference 111 is basically circular with the exception ofvarious voids 130 in the slug 106. The voids 130 are semicircular incross-section as shown. Other voids 130 in similar systems that may fallwithin the scope of this disclosure may have different shaped voids 130.

The rib 72 also has a void 132 and when a void 130 in the slug 106 isaligned with the void 132 in the rib 72, a locking pin 134 may be placedto partially extend into the void 130 in the slug 106 and the void 132in the rib 72 to thereby angularly lock the slug 106 with respect to therib 72. One of ordinary skill in the art after viewing this disclosurewill appreciate that the adjusting system 115 shown in FIG. 24 can beadjusted by rotating the slug 106 (when the locking pin 134 has beenremoved) to align various voids 130 with the void 132 in the rib 72 tocause the eccentric hole 108 to achieve a desired height with respect tothe rib 72. Once the eccentric hole 108 is positioned to achieve thedesired height, the void 130 in the slug 106 is aligned with the void132 in the rib 72 and the locking pin 134 is placed in the voids 130,132.

The voids 130 and locking pin 134 are not limited to the cross-sectionalshapes of semicircle and circular as shown. Many different shapes may beused for the voids 130 and locking pin 134. For example, thecross-sectional shapes of the voids 130 and locking pin may include asquare, rectangle, parallelogram, and a triangle. Other shapes may alsobe used.

FIGS. 25-27 illustrate additional components used in the stop system 73and adjusting system 115 described in FIG. 24. The stop shoe 74 attachesto the rib 72 via the fastener 76 which includes the bolt head 88 thebolt 80 and lock nut 82. The bolt 80 extends through the hole 94 in theboss 92 of the stop shoe 74 thereby connecting the stop shoe 74 to therib 72. The tread surface 122 and body 120 are offset by distance 126above the rib 72.

FIG. 26 illustrates a stop shoe 74 having a similar construction asdiscussed above where the stop shoe 74 includes a body 90, a second body98 (hidden from view in FIG. 26) where the bodies 90 and 98 areconnected by a tread plate 78. A fastener 76 connects the stop shoe 74to the rib 72. The tread plate 78 is raised above the rib 72 by offset126. In the position shown in FIG. 26, the offset 126 is at its highestpoint because the eccentric hole 108 is also at its highest point. Asdiscussed above, the offset 126 can be reduced by rotating the slug 106in the manner described above. Even when the stop shoe 74 is at itshighest position, the boss 92 covers the locking pin 134 keeping alocking pin 134 retained in the voids 130 and 132.

FIG. 27 is an isometric view where the stop shoe 74 is different thanthe stop shoe shown in FIG. 26. The stop shoe 74 of FIG. 27 is similarto the stop shoe shown in FIG. 25. The stop shoe 74 includes a treadsurface 122 and a body 120. The fastener 76 connects the stop shoe 74 tothe rib 72. The locking pin 134 is extending into the void 132 in therib 72 and void 130 in the slug 106. One of ordinary skill the art willappreciate after reviewing this disclosure that the various adjustingsystems 115 are not limited to specific types of stop shoe 74 andvarious stop shoes 74 can be mixed and matched with various adjustingsystems 115.

FIGS. 28 through 32 illustrate different heights the stop shoe 74 canhave with respect to the rib 72 or in other words different heights ofthe offset 126 when the adjusting system 115 is set to various levels.Certain features that should be hidden by the boss 92 or the body 120are shown in broken lines in order to illustrate these features. Thestop shoe 74 includes a body 120 having a tread surface 122. Thefastener 76 is located in the eccentric hole 108 in the slug 106. InFIG. 28 the eccentric hole 108 it is at its highest position thereforecausing the tread surface 122 also be at its highest position withrespect to the rib 72. FIGS. 29 through 32 illustrate the adjustingsystem 115 at heights below the highest level shown FIG. 28.

The voids 130 in the slug 106 and the void 132 in the rib 72 can be seenin FIGS. 28-32. The locking pin 134 is illustrated and shown to belocated in one of the voids 130 in the slug 106 and the void 132 in therib. The tip 136 of the boss 92 overhangs the locking pin 134 in orderto axially retain the locking pin 134 in place. The overhang retainingfeature of the tip 136 of the boss 92 may occur when the stop shoe 74 isin all positions including the highest position as shown in FIG. 28 andwhen the stop shoe 74 is pivoted to the extreme position in eitherrotational direction.

FIGS. 33-34 illustrate an alternate adjusting system 115. The adjustingsystem 115 shown in FIG. 33 includes a slug 106 located in a hole 124 inthe rib 72. The slug 106 includes an eccentric hole 108 similar to theeccentric hole in the slug 106 in the adjustment system 115 described inthe already mentioned and discussed figures. The hole 124 is basicallycircular with the exception of various voids 140. The voids 140 aresemicircular in cross-section as shown. Other voids 140 in similarsystems that may fall within the scope of this disclosure may havedifferent shaped voids 140.

When the void 130 in the slug 106 is aligned with the a void 140 in therib 72 (or hole 124), a locking pin 134 may be placed to partiallyextend into the void 130 in the slug 106 and the void 140 in the rib 72to thereby angularly lock the slug 106 with respect to the rib 72. Oneof ordinary skill in the art after viewing this disclosure willappreciate that the adjusting system 115 shown in FIG. 33 can beadjusted by rotating the slug 106 (when the locking pin 134 has beenremoved) to align various voids 140 with the void 130 in the slug 106 tocause the eccentric hole 108 to achieve a desired height with respect tothe rib 72. Once the eccentric hole 108 is positioned to achieve thedesired height, the void 130 in the slug 106 is aligned with the void140 in the rib 72 and the locking pin 134 is placed in the voids 130,140.

The voids 130, 140 and locking pin 134 are not limited to thecross-sectional shapes of semicircle and circular as shown. Manydifferent shapes may be used for the voids 130, 140 and locking pin 134.For example, the cross-sectional shapes of the voids 130, 140 andlocking pin may include a square, rectangle, parallelogram, and atriangle. Other shapes may also be used.

FIG. 34 illustrates a stop shoe 74 having a similar construction asdiscussed above where the stop shoe 74 includes a body 90, a second body98 (hidden from view in FIG. 74) where the bodies 90 and 98 areconnected by a tread plate 78. A fastener 76 connects the stop shoe 74to the rib 72. The tread plate 78 is raised above the rib 72 by offset126. In the position shown in FIG. 34, the offset 126 is at its highestpoint because the eccentric hole 108 is also at its highest point. Asdiscussed above, the offset 126 can be reduced by rotating the slug 106in the manner described above. Even when the stop shoe 74 is at itshighest position, the boss 92 covers the locking pin 134 keeping alocking pin 134 retained in the voids 130 and 132. Multiple voids 140can allow tread plate 78 to achieve many positions with respect to therib 72 similar to the many positions shown, for example in FIGS. 28-32.

In some instances when it is desired to have one of the stop shoes 74 ata height between levels permitted by the adjusting system 115 the stopshoe 74 may easily be removed and ground or have material added toachieve the desired level.

Many features and advantages of apparatus and methods described in thecurrent disclosure are apparent from this disclosure, and thus, it isintended by the appended claims to cover all such features andadvantages of the disclosure which fall within the true spirit and scopeof the disclosure. Further, since numerous modifications and variationswill readily occur to those skilled in the art, it is not desired tolimit the disclosure to the exact construction and operation illustratedand described, and accordingly, all suitable modifications andequivalents may be resorted to, falling within the scope of thedisclosure.

INDUSTRIAL APPLICABILITY

As can be appreciated the disclosure herein contains several industrialapplications. For example, the apparatus and method disclosed herein canprovide a function of protecting a stick 54 from damage by a thumb 66striking the stick when the thumb 66 is moved to an open position.Protection of the stick 54 allows the stick 54 to provide long andreliable service. The adjusting system 115 allows for the adjustment ofa pair of stop shoes 74 to be adjusted so that they obtain a height thatallows the stop shoes 74 to both contact either the stick 54 or apressure plate 84 on the stick 54 at the same time. Having the stop shoe74 contact or butt against the stick 54 or pressure plate 84 at the sametime helps to avoid placing too much stress on one or the other stopshoe 74 or one or the other side of a stick 54 or pressure plate 84. Thesystem described herein may also reduce the likelihood of the stick 54from being gouged or otherwise damaged by the thumb 66.

Furthermore the apparatus described herein allows for an adjustingsystem 115 and the stop system 73 to be installed at the factory ratherthan relying on a dealer or operator to install stop systems. Byallowing the manufacturer to install the stop system 73 and or adjustingsystem 115 additional quality control may be assured, and manufacturingburdens may be relieved from dealers and/or operators.

Some systems and methods described herein may provide an advantage inthat the stop system may not use a significant projection on the stick54. Omitting projections on the stick 54 may make digging specificallyshaped holes such as trenches easier for operators in than an operatordoes not need to worry about a projection on the stick 54 contacting orinterfering with the edges of the hole or trench. Furthermore, welding aprojection onto the stick 54 may change the structural stiffness of thestick 54 in a negative manner. This disclosure may be an improvementover the prior art which occasionally requires operators to mind theprojection on the stick when digging and may use a stick with acompromised structural stiffness.

What is claimed is:
 1. An adjusting system comprising: a slug definingan eccentric hole; and a locking structure defined by an outercircumference of the slug, the locking structure dimensioned andconfigured to lock the slug in a rotational orientation when the slug isplaced in a hole having a corresponding locking feature, the lockingstructure configured to permit the slug to be placed in thecorresponding hole in at least two different angular orientations andlock with the locking feature in the corresponding hole at each of theat least two different angular orientations.
 2. The adjustment system ofclaim 1, further comprising a fastener dimensioned to fit in theeccentric hole in the slug.
 3. The adjustment system of claim 2, furthercomprising a stop shoe defining a hole for the fastener to extendthrough the hole in the stop shoe and the eccentric hole in the slugthereby attaching the stop shoe to the slug.
 4. The adjustment system ofclaim 3, wherein when the fastener is in the eccentric hole and the slugis in one of the at least two different angular orientations, the stopshoe is at a first height with respect to a center of the slug, and whenthe slug is in the other of the at least 2 different angularorientations, the stop shoe is at a second height with respect to thecenter of the slug.
 5. The adjustment system of claim 1, furthercomprising a rib located on a thumb and the corresponding hole islocated in the rib.
 6. The adjustment system of claim 1, wherein thelocking structure includes flat portions on the outer circumference ofthe slug.
 7. That adjustment system of claim 6, wherein the flatportions are configured to form the shape of least one of: a square,pentagon, hexagon, and an octagon.
 8. The adjustment system of claim 7,wherein the corresponding hole defines more corners than the number ofcorners defined by the flat portions intersecting at the outercircumference of the slug.
 9. The adjustment system of claim 8, whereinthe corresponding hole defines at least twice as many corners than thenumber of corners defined by the flat portions intersecting at the outercircumference of the slug.
 10. The adjustment system of claim 1, whereinthe locking structure includes voids in at least one of the outercircumference of the slug and a wall that defines the correspondinghole, the voids each form a geometric shape when viewed in cross-sectionand a discontinuity in the other of the wall forming the hole and theouter circumference of the slug, the discontinuity having thecorresponding locking feature, the discontinuity forming a void forminga geometric shape when viewed in cross-section and a locking rod thatfits one of the voids in the slug and hole having a correspondinglocking feature to thereby rotationally lock the slug.
 11. Theadjustment system of claim 10, wherein the geometric shape of the voidsis a half circle, and the geometric shape of corresponding lockingfeature void is also a half circle and the cross-sectional shape of therod is a circle.
 12. The adjustment system of claim 10, wherein thegeometric shape of the voids is one of: a rectangle, a square, aparallelogram, and a triangle, and the geometric shape of the void inthe hole having the corresponding locking feature is one of: arectangle, a square, a parallelogram, and a triangle and thecross-sectional shape of the rod is one of a rectangle, a square, aparallelogram, and a triangle.
 13. The adjustment system of claim 10,further comprising: a second slug defining a second eccentric hole; anda second locking structure defined by the outer circumference of thesecond slug, the second locking structure dimensioned and configured tolock the second slug in a rotational orientation when the second slug isplaced in a second hole having a corresponding locking feature, thesecond locking structure configured to permit the second slug to beplaced in the second corresponding hole in at least two differentangular orientations and lock with the second locking feature in thecorresponding second hole at each of the at least two different angularorientations; first fastener and second fastener dimensioned to fit inthe eccentric hole in the slug and second slug and respectively; firstand second stop shoes defining a first and second holes for the firstand second fasteners respectively to extend through the first and secondholes in the first and second stop shoes and the eccentric hole in theslug and second slug thereby attaching the first stop shoe to the slugand the second stop shoe to the second slug and an angular orientationof the slug and second slug is selected to cause the first and secondstop shoes to evenly contact a contact surface on a stick.
 14. A methodfor adjusting stop shoes comprising: rotating a slug to a desiredangular orientation; inserting the slug into a hole; locking the slug toa particular angular orientation with locking structure attached to bothof the slug and the hole; and securing a stop shoe to the slug.
 15. Themethod of claim 14, further comprising adjusting a pair of stop shoes tohave substantially coplanar tread surfaces by rotating a slug associatedwith each stop shoe.
 16. The method of claim 14, further comprisinginserting a fastener into the stop shoe and an eccentric hole in theslug.
 17. The method of claim 16, further comprising pivoting the stopshoe about the fastener.
 18. The method of claim 14 comprising selectinga desired height of an eccentric hole in the slug and achieving desiredheight by rotating the slug.
 19. The method of claim 14, furthercomprising inserting a locking rod into a void in the slug.
 20. Anadjusting system comprising: a means for defining an eccentric hole; ameans for preventing the rotation of the means for defining an eccentrichole when the means for defining an eccentric hole is inserted into themeans for preventing the rotation of the means for defining an eccentrichole; means for abutting pivotally attached to the means for defining aneccentric hole; and a fastener pivotally connecting the means forabutting to the means for defining an eccentric hole, the fastenerextending through both the means for abutting and the eccentric hole.